Steam-engine



4 Sheets-Sheet 1. M. W. HALL. 4 STEAM ENGINE.

(No Model.)

(No Model.) Y 4 Sheets-Sheet 2. M. W. HALL.

STEAM ENGINE. No. 409,284. Patented Aug. 20, 1889.

' 4 Sheets-Sheet 3.

(No Model.) STEAM ENGINE. No. 409,284. Patehnied Aug. 20, 1889.

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(No Model.)

M. W. HALL. STEAM ENGINE.

N0. 409,284. Patented Aug. 20, 1889.

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NITED STATES PATENT OFFICE.

MILAN XV. HALL, OF BROOKLYN, NE`W- YORK.

STEAM-ENGINE.

SPECIFICATION forming part of Letters Patent No. 409,284, dated August20, 1889.

Application filed January 24, 1888. Serial No. 261,787. (No model.)

To all wtmw t may concern:

Be it known that l, MILAN lV. HALL, a citizen of the United States,residing at Brooklyn, in the county of Kings and State of New York, haveinvented certain new and useful Improvements in Steam-Engines, of whichthe following is a specification.

My invention relates to steam-engines or otheranalogous motor-engines,and is also applicable to pumps, water-meters, and other machinesoperating on analogous principles.

My invention relates to that type of engines known as revelving-cylinderengines, or those constructed with a plurality of cylinders arrangedradially around a common axis on which they are mounted to revolve, andhaving their pistons connected by pitmen, or otherwise, to a stationarycrank eccentric to said axis. The advantage of engines of this type isthat all reciprocating movements are eliminated, the movements of allthe parts being directed in circular paths, so that the loss of powerwhich in reciprocating engines is consumed in alternately impartingmomentum to the moving parts and overcoming this momentum in stoppingthem is avoided. Engines of this type are consequently well adapted forrunning at a high speed, being free from the pounding and vibrations dueto the stopping and starting of the reciprocating parts, and requiringno steam-cushions to rcceive the impact of the pistons.

The particular construction of such revolving-cylinder engines whichmost resembles my present invention, and upon which the latter is mostdirectly an improvement, may be described as follows: Two or morecylinders, usually four, are fixed rigidly together by casting them inone piece, or otherwise,their axes being arranged on equidistant radiiaround the axis of rotation, their axes being all in one planeperpendicular to said axis of rotation. These cylinders are mounted on aradial shaft, and in each cylinder is placed a single-acting piston ofthe bucket-plunger type, which pistons are connected by means of pitmento one common crank or stud which is arranged eccentrically to the axisof rotation, and is fixed in place so as to remain stationary. Each ofthe cylinders is provided with a valve-chest arranged parallel with it,and in the several valve-chests balanced piston-valves are arranged towork, all of the valves being connected through eccentric rods andstraps to one common eccentric, which is also arranged stationary and ina fixed relation to said stationary crank. The valves thus act withreference to their respective cylinders in the same manner as the valvesof reciprocating engines. The pistons, being all connected t0 thestationary crank, remain at all times equally distant from the eccentricaxis thereof, and hence the action of the steam cans-es the cylinders torevolve upon the axis of the shaft on which they are mounted, a resultwhich is due to the reaction of the pistons in pressing through theirpitmen upon the crank. rlhe movement of the pistons relatively to thecylinders is reciprocatory, but relatively to a stationary part thepistons rotate in a circular path eccentric to the path traversed by therotary cylinders. Thus there is, during the running of the engine, nochange in the direction of motion of any of the parts, and Ahence nonecessity for overcoming momentum in stopping or inertia in startingthem, so that an engine of this type should be capable of ruiming at amuch higher speed than areciprocatin g engine. The revolving cylindersare inclosed in an exterior stationary casing into which theexhaust-steam is admitted from the cylinder.

Revolving-cylinder engines as heretofore made have attained but littlepractical snccess, owing to certain defects in their construction. It isthe object of myinvention to overcome these defects and produce anengine of this type which shall be practical and economical in itsoperation, in order that it may be available as a high-speed engine fordriving dynamos, centrifugal machines, the., by direct connectiontherewith.

My invention introduces some important structural improvements andprovides means for insuring the perfect balance of the revolving partsby correcting any inequality of balance that may occur in the casting orotherwise.

In the accompanying drawings, Figure l is an end elevation of aconstruction of engine embodying my invention, the outer casing ant'shaft being in vertical section cut in tht plane of the line l l in Fig.2. Fig. 2 is e vertical axial section cut in the plane of tl' lOO line 22 in Fig. l. Fig, 3 is a vertical transverse section cut through theaxes of the steam-cylinders, as denoted by the line 3 3 in Fig. 2. Fig.4 is a vertical transverse section cut through the axes of thevalve-chests and looking in the opposite direction from Fig. 3, asdenoted by the line 4 -it in Fig. 2. Fig. 5 is a fragmentarysection of aportion of Fig. 2, showing the details ot' the valve-connections,steam-packin gs, and lubrication on a larger scale. Fig. G is a diagramillustrating the revolving movement ot' the pistons around the crankcenter. 7 is a vertical section corresponding to Fig. 3, and showing amodified construction wherein the engine has three cylinders instead oftour; and Fig. 8 is a similar section illustrating' an engine having twocylinders.

Referring first to Figs. l to 4, let A designate the outer caseiuclosing the 'working parts of the engine; B, the rotary shaft; C C,thecylinders, of which four are employed in this construction; D I), thepistons working in these cylinders; E E, the pit-men or connecting-rodsof the respective pistons,and F the crank, which in this construction isstationary.

Gr is the steam-inlet pipe, and Il the eX- haust-pipe.

The four cylinders C C are connected 'Fixedly together, preferably bybeing' all formed in one casting, lettered I. The cylinders areconnected to the shaft ll and rotate therewith. The crank F is heldstationary by being fastened in any suitable manner to the outer' case Aor to any other stationary part. The four pitmen E E all engage the onecrank-stud F and radiate therefrom to the points at which they arepivoted to the pistons.

In Fig. 3 the upper and lower pistons are shown at the end of theirstroke and the right and left hand pistons are shown at mid-stroke. Itthe rotation be assulned to be in the direction of the arrow Qc, theright-hand piston is for the momentthe only effect-ive one. Steam isentering the right-hand cylinderCthrough the steam-port e, and isexerting a pressure tending to force the piston to the left and thecylinder-head to the right. rlhe latter pressure being resisted, thereaction lin the opposite direction is transmitted through the pitman tothe crank F, as indicated by the arrow, and by reason ot the inclinationor throw ot` this pitman a lateral pressure is exerted against thecylinder C, which forces it to rotate in the direction of the arrowthereby carrying around the entire system oi' cylinders and pistons. Asthe center is passed, the next successive piston (being the upper one inFig. 3) commences to act, and during the ensuing quarter-revolution thetwo pistons are acting in co-operation, the mechanical advantage of thepreceding one, however,

diminishing as that ot the succeeding one increases. In short', theaction is the reverse of that of an engine with 'four radial equidistantstationary cylinders with their pistons all coupled to a rotary crankrevolving around the common center. rlhe four pistons are each single-acting, so thattheir action against the crank is a pushing actionand continues during only one-half of the revolution. This has theadvantage ot avoiding thie necessity ot' piston-rods and stufiing-boxesbetween the pistons and the crank. The action ot' the four pistons issuccessive, and the thrust exerted through the respective pitmen againstthe crank increases and diminishes in such relation as to result in avery nearly uniform thrust or back-pressure upon the crank-stud, andconsequently in a similarly uniform forward impetus applied to thecylinders.

It will be seen thatalthough the pistons reciprocate relatively to thecylinders, yet their actual movement is a rotary one around the crank F.As the cylinders revolve, the pistons revolve with them around the crankF as a center, and consequently in very nearly circular paths, the pathof the centers of the pitmen-joints b b being exactly circular. The axesot the pitmen-joints l) l1 are preferably arranged in the center ofgravity ot the pistons, in order that the latter may be exactly balancedin their movement around the center F. The pistons I) D, consideredrelatively to the crank-center F, have an oscillatory movement on thecenters l) b as they whirl around the crank-center, which oscillation isequal in degree to the angular throw of the pitmen, but which, occurringcoincidently with the revolution around the crankcenter, results merelyin the extreme outer and inner portions of the pistons most remote fromthe centers I) traveling in curves slightly varying from the true circletraversed by the centers b.

In order to clearly illustrate the path traversed by the pistons and itsrelation to the rotary paths of the cylinders, I have introduced thediagram, Fig. G, where the pistons are shown in elevation in theposition which they occupy when the cylinders have advanced one-eighthof a revolution beyond the position shown in Fig. The circle y denotesthe path traversed by the pitmen-joint centers l) b, and the circle .edenotes the paths traversed'by the outer ends of the cylinders.

Inasmuch as the pistons in revolving around the crank-center necessarilymove in and out along radii from the axis of the shaft B around whichthe cylinders revolve, they necessarily draw closer together as theyapproach the shaft-axis and separate .as they recede therefrom. Thisaction results in a slight acceleration in speed of the pistons duringone half of each revolution, and a corresponding retardation during theremaining halt'. These accelerations and retardations occur graduallyand without shock or vibration, and also without any loss cr waste ofpower, because they are induced through the relative movement of thecylinders and pistons so that the IOO IIO

acceleration caused by the cylinders on one side, and which might tendslightly to retard their rotation, is balanced by the retardation causedbythe cylinders on the other side, which tends to accelerate the speedof the cylinders. Furthermore, it will be observed that the accelerationof speed of the pistons is coincident with the transmission of powerthrough them and their pitmen against the crank, and their retardationis coincident with the exhausting of the steam from behind them,circumstances which tend still further to neutralize any effect whichmight otherwise result from the slight variation in the movement of thepistons from a uniformlyspeeded rotation.

The effect of centrifugal force upon the pistons tending to throw themaway from the crank center is more than neutralized during the activehalf-revolution of each piston by the pressure of live steam against itsouter side, and during the inactive half-revolution the outward tendencyof the piston is useful in expelling the exhaust-steam from thecylinder.

I will now proceed to describe more in detail the constructive 'featuresintroduced by my invention.

The valve-gear is characterized by the employment of a stationaryeccentric J, embraced by four eccentric-straps c c, which are connectedby eccentric-rods (l CZ to the four steam-valvcs V V, which moveradially in valve-chests K K, communicating with the respectivecylinders. The cylinder-casting I is formed with a concentric steamchest or chamber L, in which the eccentric J and the eccentric strapsand rods are inclosed. The valve-chests K K radiate from this chamber Lcoincidently with the radial arrangement of the cylinders, as shown inFig. et. By preference each valve-chest K is lined with a bushing 7i",in which the ports are formed. In the construction shown this bushing iscylindrical, and forms a close-working tit with the cylindrical orpiston valve V. Each valve V is essentially a single-acting Dslide-valve developed cyliudrieally around an axis parallel with itsdirection of radial motion, so that it becomes a double piston-valvewith a contraction or neck between the pistons forming thesteam-passageg for connecting the cylinder-port with the exhaust-port, and with asteanrpassage formed through the valve from end to end. Fach valve-chestis formed with a cylinder-port e, leading to the outer end of therespective cylinder C, and with an exhaust-port f opening outwardly tothe exterior of the casting I. XVhen the valve V is drawn by theeccentric toward the center of rotation, its outer end uncovers thecylinderport e, as shown at the left hand in Fig. 4L, and steam passesfrom the steam-chest L through the hollow valve and passes by the port cinto the cylinder. At the same time the diametrically-opposite valve isthrust away from the center of rotation, as shown at the right in Fig.4, so that the steam-passage g between the pistons affords communicationbetween the cylinder-port c and the exhaustport j; whereupon the steampasses from the cylinder G to the exterior and freely escapes. lVhen thevalve V is in an intermediate p0- sition, as shown'at the top andbot-tom in Fig.

'4, and as shown in Fig. 2, its outer piston,

which is of the same length as the width 0f the cylinder-port e, standsdirectly over and closes that port. By this construction of tubulardouble piston-valves the live steam. is caused to press equally againstboth ends of each valve, whereby the valves are balanced and all unduefriction is avoided. rihe action of centrifugal force establishes acontinual tensile strain upon the eccentric-rods d d, which enablestheserods to be constructed of very light material without liability' oftheir buckling', as would be the case where they are subject tothrustiiig-strains. Y

It will be understood that with the valvegear shown, or with any othertype of valvegear that may be devised, the setting of the eccentricrelatively to the crank-stud in order to give a lead to the valves, andthe extent of lap which the valves have relatively to their ports, willbe governed by the same rules as with reciprocating engines.

The crank F and eccentric J are, in the construction shown, both mountedupon and fixed rigidly to a shaft M, which is arranged xedly with itsaxis coinciding with that of the shaft B. The crank F is formed on acrank-disk N, which is fastened by bolts 7L 7L or otherwise to the endof the stationary shaft M. The four cylinders C C are east together,with an intervening chamber I) at the center, in which the disk N, crankF, and pitmen E E are arranged. rlhis chamber P extends to the left inFig. 2 sufficiently beyond the cylinders C C to admit the thickness ofthe disk N between, as shown, and this recessed portion of thecylinder-casting is formed out of contact with the disk, in order thatit may freely rotate. The disk N is constructed with a hub which projeets through the wall of the casting I to the steam-chainber L. rlheconcentric opening in the casting` I, through which this hub passes, ismade a bearing-'fit therewith atj, in order that the cylindercasting inits rotation shall turn on this hub as on a journal. On the oppositeside of the steam-chamber L the casting I is formed or provided withanother bearing at e', which turns on a portieri of the shaft M as on ajournal. rlhe shaft B is formed or oonstructed with adisk Bon its end,which disk is bolted to the cylinder-eastingl and forms a cover forclosing the chamber I between the cylinders. Thus the cylinder-casting Iis rotatively mounted on the bearings i and j, and by means of thebearings in which the shaft B turns.

The engine is constructed with an outer inclosing-case A, within whichthe moving parts are placed, and which is made stea1n-tight, by

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preference. This case is cast with a base A and is formed on one sidewith a `removable cover Q and on the other side with a removable coveror plate R. The shaft M is fastened to or formed integrally with thecover Q, and the bearing R for the shaft B is fastened toor formedintegrally with the cover R. The opening or seat against which the coverQ fits is large enough to admit the passage of the cylinders, wherebythey may be inserted within the case A. The seat or opening in the caseA, which is closed by the cover R, is large enough to admit theinsertion of the disk B on the shaft B, so that to get access to thechamber P it is only necessary to remove the cover R and disk B.

The steam-pipe G is screwed into the center of the cover Q andcommunicates with the steam-chest L through the medium of a hollow orbore m in the shaft M and lateral openings n In therein, as shown inFig. 2. The space Within the casing A exterior to the cylinder-castingconstitutes an exhaust-space, into which the exhauststeam is admittedfrom the ports f f, and from which it escapes by the exhaust-pipe Il,which may be applied at any convenient point.

The steam-chest L is packed, in order to prevent escape of steam throughthe bearings e' and j by means of diaphragm packings as best shown inFig. 5. These packings consist each of a ring p, a diaphragm q, and aring r. The smaller ring p is brazed or otherwise fastened with asteam-tight joint to the inner margin of the annular diaphragm q, andthe outer margin of the diaphragm is fastened against the inner wall ofthe steamchamber L through the medium of the ring r, which is placedagainst it, and screws or bolts which are passed through this ring andscrew into the wall of the chamber. Thus the packing turns with thecylinder-casting. The inner ring p bears against the stationary surfaceor face s just inside of the bearingjoint t or j, so that this jointcomes between thc two rings, and leakage of steam through this joint isprevented by the ring p being pressed against the face s by thesteampressure within the steam-chamber L acting against the diaphragm q.The tightness of the packing is thus proportional to the pressure of thesteam, and any wear between the ring` p and the face s is taken up bythe yielding of the diaphragm.

In order to enable the packings to be applied within the chamber L, thelatter is constructed with an annular cover or plate T, which, whenremoved, affords an opening large enough to insert the packings, andalso enabies the eccentric to be entered. The inner packing (shown atthe right) in Fig. 2 is iirst inserted and fastened in place, and theouter packing is applied to the cover T, which is put in place on theshaft M, after which the shaft is thrust into the steam-chamber untilthe cover T comes into place, whereupon the latter is fastened to thecylinder-casting' by screws inserted through a hand-hole, closed by acap Q. The crank-disk N is inserted in'to the chamber P from theopposite side, and afterward bolted to the end of the shaft M. Thechamber P is subsequently closed by screwing on the disk B', after whichthe cylinders are thrust into the casing A from the left, the shaft Bbeing passed into the bearing R and the cover Q being screwed to thecase. A belt-pulley S may subsequently be fastened on the projecting endof the shaft, if desired.

It is not necessary that the cylinder-casting I be made all in onepiece. For convenience of construction it may be preferable to make itof several pieces, which will be fitted together and united subsequentlyin such manner as to be substantially integral.

The construction by which the four pitmen E E embrace the one-crank-studF is a novel one. Each pitman is formed with an eye for engaging thecrank, these eyes being differently formed in the four pitmen. Themiddle one has a single eye. (Shown at t in Fig. 5.) This eye isembraced between two eyes t2 t2, formed on the forked end of another ofthe pitmen. Outside of these come eyes t3 t3, formed on the forked endof a, third pitman. The fourth pitman has its forked ends formed witheyes t4 1f, still farther apart, and which embrace the eyes of all theother pitmen between them. Thus the thrust of each of the pitmen is sodivided or balanced as to be substantially in the center of thecrank-pin. The pitmen-eyes do not engage the crank-'pin directly, butengage a bushing u, which fits over the crank-pin and which is united toone of the pitmen by a flange 0n its outer end, through which screws arepassed into one of the eyes t4, as shown in Fig. 2, so that this bushingis caused to turn on the crank-stud coincidently with the pitman havingthe widest 'branched end. The eyes of the other pitmen turn upon thissleeve with an oscillatory motion equal in extent to the angulardeflection of the pitmen. This construction makes a better connectionthan if each of the pitmen separately grasped the crank-stud, since thewear due to their oscillatory movement comes upon the bushing u insteadof upon the crank-pin, and since their thrust is distributed through thebushing over'the entire surface of the crank-pin. Furthermore, thecentrifugal tendency of the pistons is equalized in its effect upon thecrank, since their outward pull is directed against the bushing, againstwhich those on opposite sides pull in opposite directions, andconsequently only the resultant pressures due to the action of the steamupon the pistons are transmitted to the crank-stud.

A similar construction is applied to the eccentric-straps c c. One ofthese straps is formed integrally with a bushing u', of a width equal tothat of the working-face of the eccentric, and the other threeeccentric-straps play upon the exterior of this bushing, oscil- IOO IIO

lating thereagainst according to the angular play of the eccentric-rods.This construction has the same advantage as that just described withreference to the crank-stud connection.

Figs. 2 and 5 show means for lubricating the engine. t* in Fig. 2 is anordinary oil-cup for lubricating the bearing of the shaft B. Forlubricating the internal bearings which are subject to steam-pressure, Iprovide a lubricator U, of ordinary construction, wherein by thecondensation of steam admitted from the steam-pipe G the oil is forcedup through a sight-feed and conducted through suitable ducts to therespective bearings. The lubricator U is connected to the steam-pipe Gby a coiled pipe in, which affords an extensive radiating-surface inorder to cool and condense the steam, the water of condensation fromwhich enters the bottom of the oil-chamber, as is usual in lubricatingdevices of this character, and forces the oil out from the upper part ofsaid chamber through the si gilt-feed. I employ three sightfeeds, theone of which at the left opens directly into the steam-pipe G, in orderto supply oil to the valves and pistons, the middle one of whichconnects with a pipe or duct a, which lubricates the crank-stud and thebearing j, and the right-hand one of which connects with a pipe or ductZ, which lubricates the eccentric and the bearing i. As shown in Fig. 5,the duct a consists of a small pipe connecting at one end with thesightfeed, and at the other end `to the solid portion of the shaft M,and albore or channel extending thence through the shaft M and throughthe crank-disk N into the crank-stud F, in which it branches laterallyand terminates at the bearing-surface of this stud, another branchleading to the bearingj. The sleeve u has perforations through it toconduct the oil to the bearing-surfaces of the pitm en-eyes. The duet Z'consists of a small pipe, connecting at one end with the right-handsight-feed and at the other end to the solid portion of the shaft M, anda bore or channel extending thence into the shaft and laterally to andinto the eccentric J, and terminating at the bearing-face thereof. Thesleeve a has oil-perforations through it to conduct the oil to thebearing-surfaces of the eccentric-straps. The duct-pipe Z has a branchleading to the bearing 17. Thus the oil is supplied to all thebearing-surfaces, and its supply is under control through the medium ofthe usual adjusting-screws of the sight-feeds.

The cylinder-casting I is made, preferably, with tie portions or bracesI', extending from the outer end of each cylinder to the outer ends ofthe adjacent cylinders, in order to stiften and strengthen thestruct-ure. This casting should be perfectly balanced, in order that therotation of the engine may be unaccompanied by vibration and free fromcentrifugal strain upon the bearings. Inasmuch as it is difficult tomaintain a perfect balance of weight in the construction and iinishingof a casting,I provide means by which the parts maybe balanced in thesubsequent puttin g together of the engine. For this purpose I providefour or other suitable number of radial screws J, on which are placedcounter-weights IV NV, which maybe adj usted inwardly or outwardly uponthe screws and fastenedv in place thereon by set-nuts, as shown. By theproper adjustment of these weights a perfect balance of the engine maybe secured.

I have not illustrated any reversing-gear for my engine, as engines ofthis character will not ordinarily need to be reversible, and as anyordinary or known constructions of reversing-gear may be readily appliedto it by simple mechanical adaptation and without necessarily involvingthe exercise of invention, or the engine may be reversed by reversingthe direction of the iiow of steam through it-that is to say, by causingthe steam to enter at the pipe II and to escape at the pipe G-tl1e meansfor accomplishing which are so obvious as to require no description. j

My improved engine may have more or less than four cylinders andpistons. In Fig. 7 I have shown an engine constructed with threecylinders radiating equidistantly from the center of rotation, and inFig. S I have shown an engine having only two cylinders arranged ondiametrically-opposite sides of the center of rotation. This latterconstruetion, however, I do not recommend, as the balance of the pistonswill not be as perfect as in a three or four cylinder engine, and forthe further reason that if the pistons are single-acting two dead-pointsare formed.

My improved engine may be modified in various ways without departingfrom its essential features-as, for example, by the substitution ofother well-known types of valve- .operating mechanisms or valve-gearsfor the particular valve-gear which I have shown. Any known type ofautomatic variable cutoff, or other type of governor, may also beapplied to it.

I claim as my invention the hereinbeforedescribed improvements in steamor other engines and other analogous machines, defined, respectively, asfollows, substantially as hereinbefore specified, namely l. An engineconstructed with a plurality of cylinders arranged radially aroundacommon axis, with an equal number of valvechests having portscommunicating with said cylinders, and with a concentric revolvingsteam-chest between said valve-chests, in combination with an axialrotative shaft on which said cylinders and valve-chests are mounted, acrank arranged eccentrically to said axis, pistons in said cylinders,pitmen engaging said crank and connecting with said pistons, valves insaid valve-chests, a valvegear for movingsaid valves, and a steaminletcommunicating with said concentric steam-chest.

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vsteam-chests for moving said valves.

3. In an engine, the combination of an inclosing-case, a stationaryshaft, and a crank formed on said shaft, with a rotary shaft in linewith the axis of said stationary shaft, a ,plurality ofradially-arranged cylinders fixed to said 'rotative shaft and having abearing upon said stationary shaft and formed with valve-chests havingports communicating with the cylinders, and a steam-chest concentricallyembracing said stationary shaft, a steam-inlet passage through saidstationary shaft opening into said steam-chest, valves 'in saidvalve-chests, and a valve-gear in said steam-chest for moving saidvalves.

a. In an engine, the combination of an inclosing-case, a stationaryshaft, a crank formed on said shaft, and a steam -inlet passage throughsaid shaft, with a rotary shaft in line with the axis of said stationaryshaft, a plurality of radially-arranged cylinders fixed to said rotativeshaft and formed with a steam-chest concentrieally embracing and bearingon said stationary shaft, and into which said steaminlet passage opens,pistons in said cylinders, pitmen engaging said stationary crank andconnecting with said pistons, and packings applied at the bearing-jointsbetween said steam-chest and stationary shaft to prevent escape of steamfrom said chest through said joints.

5. In a revolving-cylinder steam-engin e, the combination of arelatively rotary shaft and steam-chamber, the one having rotativebearings upon the other and the one part formed with a facesubstantially perpei'idicular to the axis of rotation, with a packingfor said bearings, consisting of a ring arranged concentrically againstsaid perpendicular face, and

an annulardiaphragm fastened to said ring at one margin, bridging thebearing-joint to be packed, and fastened at its opposite margin to theother part, whereby the steam-pressure against said ring and diaphragmacts to press said ring against said perpendicular face.

6. In an engine, the combination of an inclosing-case constructed with aremovable cover, and with a stationary shaft fixed to said cover, and acrank formed on said shaft, a rotary shaft in line with said stationaryshaft, a plurality of radially-arranged cylinders fixed to said rotaryshaft, pistons in said cylinders, and pitmen engaging said stationarycrank and connecting with said pistons.

7. In an engine, the combination of a stationary lshaft and a crankformed thereon, a rotary shaft in line with the axis of said stationaryshaft, a plurality of radially-arranged cylinders fixed to said rotativeshaft and formed with a steam-chest concentrically embracing and bearingon said stationary shaft, pistons in said cylinders, pitmen engagingsaid stationary crank and connecting with said pistons, a stationaryeccentric fixed on said stationary shaft, valves for admitting steamfrom said steam-chest to said cylinders, and eccentric straps and rodsconnecting to said valves.

S. An engine constructed with a plurality of radially-arranged cylindersmounted to rotate around an axis, in combination with pistons in saidcylinders, a crank arranged eccentrically to said axis, mechanicalconnections between said crank and said pistons, and one or moreadjustable counter-weights applied to said cylinders, whereby the lattermay be adjusted to a correct balance around the axis of rotation.

9. An engine constructed with a plurality of radially-arranged cylindersmounted to rotate around an axis, in combination with radial screwsattached to said cylinders and adj ustable counter -weights mounted onsaid screws and adjustable toward and from the axis of rotation.

In witness whereof I- have hereunto signed my name in the presence oftwo subscribing witnesses.

MILAN W. HALL.

Vitnesses:

ARTHUR C. FRAsER, GEORGE H. FRASER.

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